Imagine that the history of the universe is compressed into one year?with the big bang occurring in the first seconds of New Year?s Day, and all our known history occurring in the final seconds before midnight on December 31. Using this scale of time, each month would equal a little over a billion years. Here?s a closer look at when important events would occur when we imagine the universe in one year.

TheUniverse in One Yearwas inspired by the late astronomer, Carl Sagan (1934-1996). Sagan was the first person to explain the history of the universe in one year?as a ?Cosmic Calendar??in his television series,Cosmos.